Rubidium hydroxide RbOH

Rubidium hydroxide (RbOH) is very hygj-oscopic (absorbs large amounts of water for its weight). It is also an excellent absorber of carbon dioxide. Rubidium hydroxide can be used to etch glass and as an electrolyte in low-temperature electric storage batteries for use in vehicles in the subarctic. 

Rubidium acid salts are usually prepared from rubidium carbonate or hydroxide and the appropriate acid in aqueous solution, followed by precipitation of the crystals or evaporation to dryness. Rubidium sulfate is also prepared by the addition of a hot solution of barium hydroxide to a boiling solution of rubidium alum until all the aluminum is precipitated. The pH of the solution is 7.6 when the reaction is complete. Aluminum hydroxide and barium sulfate are removed by filtration, and rubidium sulfate is obtained by concentration and crystallization from the filtrate. Rubidium aluminum sulfate dodecahydrate [7488-54-2] (alum), RbA SO 12H20, is formed by sulfuric acid leaching of lepidolite ore. Rubidium alum is more soluble than cesium alum and less soluble than the other alkali alums. Fractional crystallization of Rb alum removes K, Na, and Li values, but concentrates the cesium value. Rubidium hydroxide, RbOH, is prepared by the reaction of rubidium sulfate and barium hydroxide in solution. The insoluble barium sulfate is removed by filtration. The solution of rubidium hydroxide can be evaporated partially in pure nickel or silver containers. Rubidium hydroxide is usually supplied as a 50% aqueous solution. Rubidium carbonate, Rb2C03, is readily formed by bubbling carbon dioxide through a solution of rubidium hydroxide, followed by evaporation to dryness in a fluorocarbon container. Other rubidium compounds can be formed in the laboratory by means of anion-exchange techniques. Table 4 lists some properties of common rubidium compounds. 

Nitric acid HNO3 Rubidium hydroxide RbOH... 

The rubidium hydroxide of commerce 31 is a monohydrated rubidium hydroxide, RbOH.H20, which melts at 145°, and at 350° it is completely dehydrated to RbOH. At a higher temp, it begins to peroxidize and attack the crucible. The heat of soln. of the monohydrate is 3 702 Cals, at 15°. The commercial csesium hydroxide is likewise a monohydrated csesium hydroxide, Cs0H.H20 it melts at 180°, and is completely dehydrated between 400° and 500°, and at the same time the mass begins to peroxidize. To prepare the pure hydroxide, it must be dehydrated in a current of dry hydrogen at 500°. The heat of soln. of the monohydrate is 4-317 at 15°. 

Jew, Park and coworkers performed systematic investigations to develop a more efficient system for the asymmetric synthesis of a-alkylalanines by chiral phase-transfer catalysis [31]. Eventually, sterically more demanding 2-naphthyl aldi-mine tert-butyl ester 14 was identified as a suitable substrate, and its alkylation in the presence of stronger base rubidium hydroxide (RbOH) and 0(9)-allyl-N-2, 3, 4 -trifluorobenzyldihydrocinchonidinium bromide (6a) at lower reaction temperature led to the highest enantioselectivity (Scheme 2.11). 

Rubidium hydroxide, RbOH.—The hydroxide is formed by dissolving the metal in water, or by the action of barium hydroxide on rubidium sulphate. It is a very deliquescent substance, and is volatilized by heat. Its melting-point8 is 301° C., and its density9 3-203 at 11° C. The latent heat of fusion per mol. is 1-614 Cal.10 the heat of formation from the elements is 101-99 Cal.11 A monohydrate and a dihydrate have been described.12... 

Rubidium hydroxide RbOH 1310-82-3 102.476 gray-wh orth cry Iiyg 386 3.2 173 sFtOH... 

Rubidium hydroxide RbOH Stronger base and more Exothermic reactions with... 

Rubidium hydroxide RbOH Not readily available Not readily available 180 (15 = 0 Rare... 

Lithium hydroxide, LiOH Sodium hydroxide, NaOH Potassium hydroxide, KOH Rubidium hydroxide, RbOH Cesium hydroxide, CsOH... 

---